1. Field of the Invention
The present invention relates to a method for manufacturing long size concrete panels having penetrating hollows therein and an apparatus for putting the method into practice.
2. Description of the Prior Art
In the manufacturing of long size panels, there have heretofore been known the following methods, namely;
1) a method comprising feeding a soft kneaded concrete material into a molding box, imparting vibrations to the concrete material to compact into moldings and setting the moldings; and PA1 2) a method comprising feeding a fairly hard kneaded concrete material into a molding box by a concrete material feeding device moving on a long floor, imparting vibrations to the concrete material from above to compact it wherein hollows are formed in the compacted concrete material by thrusting into the concrete material a core member which is adapted to be moved by a strained guide wire in accordance with the movement of the concrete material feeding device; curing and setting the concrete material; and cutting the concrete material into desired sizes. PA1 continuously feeding pallets onto a conveyor; PA1 feeding a concrete material onto the pallets; PA1 continuously pressing pressure frames against the concrete material from the upper side and both lateral sides of the concrete material while imparting vibrations to the pressure frames; PA1 forming hollows in the concrete material by thrusting a rotary screw-type core rod therethrough and molding the material into a panel shape; and PA1 cutting the molded concrete material into a length corresponding to the length of each pallet. PA1 concrete material feeding means for continuously feeding a concrete material onto pallets which are continuously conveyed by a conveyor; PA1 pressure frames for vibrating and pressing the concrete material from the upper side and both lateral sides thereof; PA1 a rotary screw-type core rod for forming hollows in the concrete material being vibrated and pressed; and PA1 cutting means shifting in accordance with the movement of the conveyor to cut the molded concrete material into the same length as the length of each of the pallets.
In order to produce long size concrete panels as set forth above, a very wide floor area is required for laying concrete molding materials side by side on the same floor and performing molding and drying operations. Further, it is difficult to continuously feed concrete materials and continuously mold on the same site because of difficulties in controlling the processing conditions. Further, a large crane is needed to carry away the molded articles after drying from the above-mentioned wide concrete-manufacturing site. Such a manufacturing plant requires large capital investments. Accordingly, there has been a demand for establishment of a highly efficient continuous manufacturing process of long size concrete panels.